Apatosaurus
Apatosaurus, formerly known as Brontosaurus, is a genus of sauropod dinosaurs that lived about about 161-144 million years ago, during the Jurassic period. It was one of the largest land animals that ever existed, about 4.5-6 meters (15-20 feet) tall at the hips, with a length of up to 30 meters (100 feet) and a mass up to 40 metric tonnes (44 tons). Environment It was believed that Apatosaurus was too massive to support its own weight on dry land, so it was theorized that the sauropod must have lived partly submerged in water, perhaps in a swamp. Recent findings do not support this. In fact, like its relative Diplodocus, Apatosaurus was a grazing animal with a very long neck, and a long tail that served as a counterweight. Fossilized footprints indicate that it probably lived in herds. To aid in processing food, Apatosaurus may have swallowed gizzard stones (gastroliths) the same way many birds do today — its jaws alone were not sufficient to chew tough plant fibers. Classification and history In 1877, Othniel Charles Marsh published notes on his discovery of the Apatosaurus, and then in 1879 described another, more complete dinosaur — the Brontosaurus. In 1903, it was discovered that the apatosaur was in fact a juvenile brontosaur, and the name Apatosaurus, having been published first, was deemed to have priority as the official name; Brontosaurus was relegated to being a synonym. The name was not formally removed from the records of paleontology until 1974. Fossils of this animal have been found in Nine Mile Quarry and Bone Cabin Quarry in Wyoming, and at sites in Colorado, Oklahoma, Utah, USA. Species *''A. ajax'' is the type species of the genera, and was named by the paleontologist Othniel Charles Marsh in 1877 after Ajax, the hero from Greek mythology. It is the holotype for the genera, and two partial skeletons have been found including part of a skull. *''A. excelsus'' (originally Brontosaurus) was named by Marsh in 1879. It is known from six partial skeletons, including part of a skull, which have been found in the United States, in Oklahoma, Utah, and Wyoming. *''A. louisae'' was named by William Holland, in 1915. It is known from one partial skeleton, which was found in Colorado, in the United States. Robert T. Bakker made A. yahnahpin the type species of a new genus, Eobrontosaurus in 1998, so it is now properly Eobrontosaurus yahnahpin. It was named by Filla, James and Redman in 1994. One partial skeleton has been found in Wyoming. Description Apatosaurus was a large, long-necked quadrupedal animal with a long, whip-like tail. Its forelimbs were slightly shorter than its hindlimbs. One measurement places the total length of the species Apatosaurus louisae at 22 m (72 ft).3 It was roughly the weight of four elephants.One specimen of A. excelsus was estimated to weigh 25,952 kg (57,210 lb)estimates for A. louisae were 20,600 kg (45,000 lb)3 and 22,407 kg (49,400 lb).Other estimates of the body mass of adult Apatosaurus species range from 18,000 kg (40,000 lb) to 35,000 kg (77,000 lb). A microscopic study of Apatosaurus bones concluded that the animals grew rapidly when young and reached near-adult sizes in about 10 years. The skull was small in comparison with the size of the animal. The jaws were lined with spatulate teeth, which resembled chisels, suited to an herbivorous diet. Like other sauropods, the vertebrae of the neck were deeply bifurcated; that is, they carried paired spines, creating a wide and deep profile for the neck. The apparently massive neck was, however, filled with an extensive system of weight-saving air sacs. Apatosaurus, like its close relative Supersaurus, is notable for the incredibly tall spines on its vertebrae, which make up more than half the height of the individual bones. Also unusual among diplodocids is the shape of the tail, which is comparatively thin in breadth and short in height, a profile caused by the vertebral spines decreasing in height rapidly the farther they are from the hips. Apatosaurus also had very long ribs compared to most other diplodocids, giving it an unusually deep chest. The limb bones were also very robust.An article that appeared in the November 1997 issue of Discover Magazine reported research into the mechanics of Apatosaurus tails by Nathan Myhrvold, a computer scientist from Microsoft. Myhrvold carried out a computer simulation of the tail, which in diplodocids like Apatosaurus was a very long, tapering structure resembling a bullwhip. This computer modeling suggested that sauropods were capable of producing a whip-like cracking sound of over 200 decibels, comparable to the volume of a cannon Popular Culture Apatosaurus is one of the most recognizable dinosaurs. It has appeared a lot of times in pop culture. Brontosaurus has often been depicted in cinema, beginning with Winsor McKay's 1914 classic Gertie the Dinosaur. The 1925 silent film The Lost World featured, using special effects by Willis O'Brien, a battle between a Brontosaurus and an Allosaurus but the former inaccurately had a very bendy neck. When George Lucas made his special edition of Star Wars Episode IV: A New Hope in 1997, he added some large, long-necked animals based on the Brachiosaurus digital model from the earlier film Jurassic Park. At an early stage he altered the CG department's suggested name "Bronto", taken from Brontosaurus, to 'Ronto'. In the movie The Land Before Time and the sequels a Apatosaurus named Littlefoot was one of the main characters. Sinclair Oil has a long history of being a fixture on American roads (and briefly in other countries) with its green dinosaur logo and mascot, an Apatosaurus (Brontosaurus). While Sinclair's early advertising included a number of different dinosaurs, eventually only Apatosaurus was used as the official logo, due to its popular appeal.37 The Brontosaurus is the main plot focus of the 1985 movie Baby: Secret of the Lost Legend, in which a family of Brontosaurs are found still living in Africa.﻿ Apatosaurus was in the third segment, the Jurassic segment of the famous documentary When Dinosaurs Roamed America, where a herd of them were hunted by a pack of Allosaurus. ﻿ Gallery DSCN2040.jpg Brontosauri di Heinrich Harder.jpg CK5T.jpg Brontosauri di Charles Knight.jpg Brontosauro Schleich.JPG Brontosauro.gif 20115715.jpg Brontosauro (italia in miniatura).JPG Dinosaur_-_brontosaurus_(PSF).png Vecchia illustrazione di brontosauro.jpg Illustrazione di Brontosauro.jpg Brontosaurus Excelsus.jpg Img104.jpg Dinosaur Train Apatosaurus.png Fantasia Brontosaurus.JPG|Fantasia Brontosaurus 024_Brontosaurus.jpg Category:Dinosaurs of North America Category:Diplodocoids Category:Jurassic dinosaurs Category:Morrison fauna Category:Sauropods Category:Zoo Tycoon Dinosaur Digs Creatures Category:Saurischians Category:Late Jurassic dinosaurs Category: Diapsid Reptiles Category:Reptiles Category:Prehistoric animals of North America Category:Prehistoric reptiles of North America